1. Field of the Invention
This invention relates to exercising equipment, and more particularly to exercising equipment which is so arranged that the user of the equipment can perform exercises simulating the climbing of a flight of stairs.
2. Description of the Prior Art
One form of exercising equipment is disclosed in German Pat. No. 523,174, and comprises a pair of foot-supporting members which can slide along a pair of inclined tracks. The foot-supporting members are linked by a rope which passes over a V-grooved pulley, so that downward movement of one foot-supporting member is accompanied by rotation of the pulley, and by upwards movement of the other foot-supporting member. In operation, the user of the equipment stands with one foot on each of the foot-supporting members, and transfers his weight alternately on to one foot and then on to the other, so that the foot-supporting members move up and down in antiphase, and the user has to lift his body weight each time he transfers it from one foot-supporting member to the other; in this way, the climbing of a flight of stairs is simulated. An adjustable brake is provided to retard the rotation of the V-grooved pulley, so that the downward movement of whichever foot-supporting member carries the user's weight is braked, and the work done by the user in lifting his body weight is dissipated as heat in the brake. A releasable latch is also provided, to prevent rotation of the V-grooved pulley until the user has lifted his body weight through the full difference in height between the foot-supporting members.
With this previously-disclosed form of exercising equipment, the frictional resistance opposing rotation of the pulley is primarily dependent on the setting of the brake, so that the brake has to be adjusted to match the frictional resistance to the weight of different users. Also, this previously-disclosed form of exercising equipment has a number of moving parts, of which at least the pulley has to be rotatably mounted on bearings, which may need attention such as lubrication. The presence of these moving parts contributes to the complexity and cost of the equipment.
Another form of exercising equipment is disclosed in U.S. Pat. No. 3,970,302, and comprises a pair of foot-supporting members, each of which can move up and down an inclined track. The foot-supporting members are linked by a cable which is guided around a number of pulleys, so that the foot-supporting members move in anti-phase; the cable is also connected to a rocking lever, whose movement is damped by a pair of telescopic hydraulic shock absorbers. The shock absorbers retard the downward movement of whichever foot-supporting member carries the user's weight, and thus absorb the work done by the user.
This form of exercising equipment develops a force in opposition to the movement of the foot-supporting members which is, at least approximately, proportional to the speed of this movement, and which can also be adjusted by adjusting the point of connection of the shock absorbers to the rocking lever. Thus, with this form of equipment also, it is necessary to adjust the equipment to match users of different weights, since if no such adjustment were made, the speed of the foot-supporting members would increase in proportion to increases in the body weight of the user. Also, this form of exercising equipment has a considerable number of moving parts associated with the damping mechanism, and these parts may periodically require lubrication. The moving parts also increase the complexity and cost of the equipment; in particular, the use of hydraulic shock absorbers is a comparatively expensive way of providing energy adsorption, and also introduces the possibility of oil spillage.
It is an object of the present invention to provide exercising equipment of the type which allows the climbing of stairs to be simulated, which does not require adjustment to allow it to be used by users of different weights, has a minimum number of moving parts, does not require lubrication, and employs a simple arrangement for dissipating as heat the work done by the user.